The role of coherent structures on heat transfer at near-wall and free-surface boundary layers

摘要

The role of coherent structures responsible for heat transfer at near-wall and free-surface turbulent boundary layers has been investigate in this study. Databases fromdirect numerical simulation of fully developed free surface turbulence at Re = 150, based on the wall shear velocity and channel height, are used to identify coherent structures intensifying heat transfer rate at both boundary layers. The results of this study reveal that the effect of boundary condition on formation of coherent structures is critical and special treatment for the free-surface turbulent boundary layer is required to model turbulent heat transfer across the free surface.